vmm: config: Switch GenericVhostUserConfig to use PciDeviceCommonConfig

Switch GenericVhostUserConfig over to using the newly extracted struct
members as used by all PCI based devices. The use of #[serde(flatten)]
means that this change has no impact on the JSON format that the data is
stored as.

As generic vhost-user devices do not support being placed behind an
IOMMU an error is now raised if iommu is set. This can't happen via the
CLI but could via the JSON/API.

Signed-off-by: Rob Bradford <rbradford@meta.com>

vmm/src/config.rs

@@ -1861,11 +1861,7 @@ impl GenericVhostUserConfig {
             }
             _ => {}
         }
-        let id = parser.get("id");
+        let pci_common = PciDeviceCommonConfig::parse(vhost_user)?;
-        let pci_segment = parser
-            .convert("pci_segment")
-            .map_err(Error::ParseGenericVhostUser)?
-            .unwrap_or_default();
         let mut converted_queue_sizes: Vec<u16> = Vec::new();
         for (offset, &queue_size) in queue_sizes.iter().enumerate() {
             match queue_size.try_into() {
@@ -1879,30 +1875,19 @@ impl GenericVhostUserConfig {
         }
 
         Ok(GenericVhostUserConfig {
+            pci_common,
             socket: socket.into(),
             device_type,
-            id,
-            pci_segment,
             queue_sizes: converted_queue_sizes,
         })
     }
 
     pub fn validate(&self, vm_config: &VmConfig) -> ValidationResult<()> {
-        if let Some(platform_config) = vm_config.platform.as_ref() {
+        if self.pci_common.iommu {
-            if self.pci_segment >= platform_config.num_pci_segments {
+            return Err(ValidationError::IommuNotSupported);
-                return Err(ValidationError::InvalidPciSegment(self.pci_segment));
-            }
-
-            if let Some(iommu_segments) = platform_config.iommu_segments.as_ref()
-                && iommu_segments.contains(&self.pci_segment)
-            {
-                return Err(ValidationError::IommuNotSupportedOnSegment(
-                    self.pci_segment,
-                ));
-            }
         }
 
-        Ok(())
+        self.pci_common.validate(vm_config)
     }
 }
 
@@ -3054,7 +3039,7 @@ impl VmConfig {
             for generic_vhost_user_device in generic_vhost_user_devices {
                 generic_vhost_user_device.validate(self)?;
 
-                Self::validate_identifier(&mut id_list, &generic_vhost_user_device.id)?;
+                Self::validate_identifier(&mut id_list, &generic_vhost_user_device.pci_common.id)?;
             }
         }
 
@@ -3521,7 +3506,8 @@ impl VmConfig {
         // Remove if generic vhost-user device
         if let Some(generic_vhost_user) = self.generic_vhost_user.as_mut() {
             let len = generic_vhost_user.len();
-            generic_vhost_user.retain(|dev| dev.id.as_ref().map(|id| id.as_ref()) != Some(id));
+            generic_vhost_user
+                .retain(|dev| dev.pci_common.id.as_ref().map(|id| id.as_ref()) != Some(id));
             removed |= generic_vhost_user.len() != len;
         }
 
@@ -4292,10 +4278,13 @@ id=\"{id}\",pci_segment={pci_segment},queue_sizes={queue_sizes}"
             assert_eq!(
                 config.unwrap(),
                 GenericVhostUserConfig {
+                    pci_common: PciDeviceCommonConfig {
+                        id: Some(id.to_owned()),
+                        pci_segment: u16::try_from(pci_segment).unwrap(),
+                        ..Default::default()
+                    },
                     socket: socket.into(),
-                    id: Some(id.to_owned()),
                     device_type: u32::try_from(virtio_id).unwrap(),
-                    pci_segment: u16::try_from(pci_segment).unwrap(),
                     queue_sizes: queue_sizes
                         .0
                         .iter()

vmm/src/device_manager.rs

@@ -3150,11 +3150,11 @@ impl DeviceManager {
         &mut self,
         generic_vhost_user_cfg: &mut GenericVhostUserConfig,
     ) -> DeviceManagerResult<MetaVirtioDevice> {
-        let id = if let Some(id) = &generic_vhost_user_cfg.id {
+        let id = if let Some(id) = &generic_vhost_user_cfg.pci_common.id {
             id.clone()
         } else {
             let id = self.next_device_name(GENERIC_VHOST_USER_DEVICE_NAME_PREFIX)?;
-            generic_vhost_user_cfg.id = Some(id.clone());
+            generic_vhost_user_cfg.pci_common.id = Some(id.clone());
             id
         };
 
@@ -3191,7 +3191,7 @@ impl DeviceManager {
                     as Arc<Mutex<dyn virtio_devices::VirtioDevice>>,
                 iommu: false,
                 id,
-                pci_segment: generic_vhost_user_cfg.pci_segment,
+                pci_segment: generic_vhost_user_cfg.pci_common.pci_segment,
                 dma_handler: None,
             })
         } else {
@@ -5049,7 +5049,7 @@ impl DeviceManager {
         &mut self,
         generic_vhost_user_cfg: &mut GenericVhostUserConfig,
     ) -> DeviceManagerResult<PciDeviceInfo> {
-        self.validate_identifier(&generic_vhost_user_cfg.id)?;
+        self.validate_identifier(&generic_vhost_user_cfg.pci_common.id)?;
 
         let device = self.make_generic_vhost_user_device(generic_vhost_user_cfg)?;
         self.hotplug_virtio_pci_device(device)

vmm/src/vm_config.rs

@@ -498,12 +498,10 @@ impl ApplyLandlock for FsConfig {
 
 #[derive(Clone, Debug, PartialEq, Eq, Deserialize, Serialize)]
 pub struct GenericVhostUserConfig {
+    #[serde(flatten)]
+    pub pci_common: PciDeviceCommonConfig,
     pub socket: PathBuf,
     pub queue_sizes: Vec<u16>,
-    #[serde(default)]
-    pub id: Option<String>,
-    #[serde(default)]
-    pub pci_segment: u16,
     pub device_type: u32,
 }